FDA expands Kalydeco label based on in vitro data

FDA expanded the label of cystic fibrosis drug Kalydeco ivacaftor to include 23 new disease-causing mutations, based on results from an in vitro cell model system. The agency said the approach "provides a pathway for adding additional, rare mutations of the disease, based on laboratory data."

The drug's updated label now says it is indicated to treat CF in patients ages ≥2 with a CF transmembrane conductance regulator (CFTR) mutation responsive to Kalydeco "based on clinical and/or in vitro assay data."...